This proposal requests funds for instrumentation to facilitate improved MR Spectroscopic Imaging (SI) and its application for in vivo spectroscopic measurements of brain, heart and muscle, with clinical human studies and animal models. Funds are requested for a field gradient and shim coil set and a computer workstation for processing and review of SI data. Studies will use SI to measure distributions of MR observable proton and phosphorus metabolites in a variety of tissues. This includes ongoing clinical spectroscopy studies of ischemia, malignancy and AIDS, as well as animal studies of infarction and malignancy. These studies are ultimately expected to improve our understanding of disorders such as stroke, myocardial ischemia and cancer, with improved methods of diagnosis and monitoring therapy. The requested instrumentation will be used by PHS funded research projects for Spectroscopic Imaging studies. Projects are: i. Improved SI of proton metabolites in vivo. ii. Improved 31P SI techniques for clinical investigation of brain, heart and liver, including quantitation methods. iii. SI of brain ischemia and infarction iv. SI of animal cancer v. NNR metabolic studies of brain ischemia and reperfusion vi.In vivo brain 31P metabolism in AIDS dementia vii. MRS studies of Deep White Matter Lesions viii. SI of Human Heart ix. SI of the Rat Gastrocnemius Muscle x. Diffusion and perfusion imaging of cerebral function in animals